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<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <script>
        // split
        // join

        var arr = ['张三', '李四', '王五'];

        var str = '张三,李四,王五'
    </script>

</body>

</html>